4MM CS X 28MM ID BLACK BUNA 70D

H4X28 is a black Buna-N (Nitrile) 70 Shore A O-Ring built to an inside diameter of 28 mm (1.102 in), a cross section of 4 mm (0.157 in), and an outside diameter of 36 mm (1.42 in). In service, this o-ring seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces.

This material stands up to hydraulic fluids, water, and greases and lubricants. That behavior comes from the compound itself: Buna-N (Nitrile) delivers low compression set under sustained load, reliable performance in both static and dynamic service. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Exposure to strong acids or ozone and direct sunlight will shorten service life.

You will find this material specified across agricultural equipment, automotive, and fluid power.

Reference part number H4X28 when ordering; the item is sold individually. Unit weight is approximately 1.5588 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.